JPH05222119A - Polymer containing methacrylimide group - Google Patents

Abstract

PURPOSE:To obtain a polymer excellent in heat resistance and moldability and in the balance between these properties by incorporating two kinds of structural methacrylimide units as the essential components in specific amounts. CONSTITUTION:The title polymer has a molecular structure made up of repeating units (A) to (C) represented by formulae I to III, respectively, in amounts of 40-80wt.%, 20-60wt.%, and 0-10wt.%, respectively, based on the polymer. In formulae I to III, R1 is H or a 1-18C aliphatic, aromatic, or alicyclic hydrocarbon group and R2 is a carboxy, a 1-6C aliphatic ester group, or a 1-18C aliphatic, aromatic, or alicyclic amide group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methacrylimide group-containing polymer which is excellent in heat resistance, molding processability and thermal stability and has a good balance of these physical properties.

[0002]

2. Description of the Related Art Methyl methacrylate polymers are widely used in various industrial fields such as automobiles, electric / electronic fields, and building materials fields by taking advantage of their excellent transparency, weather resistance and mechanical properties. However, since the methyl methacrylate polymer has a low heat distortion temperature of around 100 ° C., it is currently difficult to use it in an environment where heat resistance higher than this is required. Polycarbonate is used as a resin having transparency and heat resistance, but the practical heat resistance temperature is less than 140 ° C., which is not sufficient depending on the application.

By the way, as a method of improving the heat resistance of a methyl methacrylate polymer, a method of utilizing a side chain reaction of the methyl methacrylate polymer to imidize is known. Examples of this imidization method include a method in which a methyl methacrylate polymer is subjected to a thermal decomposition condensation reaction with a primary amine (US Pat. No. 2,146,209), a methyl methacrylate polymer is ammonium hydroxide, an alkylamine phosphate. Method of reacting with (US Pat. No. 3,284,425)
Specification), or a method of reacting a methacrylic acid ester polymer with ammonia or a primary amine in an extruder (Japanese Patent Publication No. 60-38404).

[0004]

However, in these conventional imidization techniques, most of them are imidized using a single imidizing agent, and as a result, the imidized polymer is a single imidizing agent. It has a methacrylimide structure. Therefore, for example, a polymer imidized with methylamine has a heat distortion temperature of 160 to 180 ° C., and sufficient heat resistance is not yet obtained. Further, a polymer which is 100% imidized with aniline has a heat distortion temperature of 230 ° C. and shows excellent heat resistance, but has defects in mechanical strength and moldability.

On the other hand, even in a polymer having a low methacrylimide group content with a reduced imidization ratio and improved mechanical strength and fluidity, methacrylic acid ester and its derivative residue are present in the polymer, so that the polymer may be removed under high temperature atmosphere. Thermal stability failure such as decomposition of the resin occurs, and practically satisfactory results have not been obtained as a heat resistant molding material. In addition, Japanese Examined Japanese Patent Publication No.
In Example 44 of JP-A-04-2004, it is disclosed that a mixture of 5% ammonia and 95% butylamine is used as an imidizing agent. What is the repeating unit of methacrylimide group derived from such imidizing agent? No specific description or suggestion is made regarding whether heat resistance, molding processability, thermal stability, etc., and balance among these physical properties are excellent due to the presence in a large proportion.

[0006]

In view of the above-mentioned circumstances, the present inventor has found that a methacrylimide group-containing polymer having excellent heat resistance, molding processability, particularly fluidity and thermal stability, and a good balance of these physical properties. As a result of diligent examination to obtain coalescence,
The present inventors have found that the intended purpose can be achieved by forming at least two different methacrylimide structural units as constituent components of a polymer in a content within a specific range, and achieved the present invention.

The gist of the present invention is a methacrylimide group-containing polymer in which each repeating unit represented by the following general formulas (I), (II) and (III) is contained in the copolymer. The general formula (I) in the polymer:
In the methacrylimide group-containing polymer, the content of the repeating unit represented by (III) is 40 to 80% by weight, 20 to 60% by weight, and 0 to 10% by weight, respectively, based on the weight of the polymer.

[0008]

[Chemical 1]

(In the above formulas (I), (II) and (III),
R _{1 represents a} hydrogen atom or an aliphatic, aromatic or alicyclic hydrocarbon group having 1 to 18 carbon atoms, R ₂ represents a carboxyl group, an aliphatic ester group having 1 to 6 carbon atoms or 1 carbon atom
To 18 aliphatic amide groups, aromatic amide groups or alicyclic amide groups. )

The methacrylimide group-containing polymer of the present invention is different from the conventionally proposed methacrylimide group-containing polymer having a single methacrylimide group structural unit.
By containing at least two different methacrylimide structural units of the above repeating units (I) and (II) as essential components in the respective ranges of specific contents, heat resistance, molding processability, thermal stability, etc. The greatest feature is that a methacrylimide group-containing polymer, which has not been heretofore found to be excellent in physical properties and is excellent in balance of these physical properties, can be obtained.

The methacrylimide structural unit of the repeating unit (I) in the present invention has a phenylmethacrylimide group, and one hydrogen atom of the phenyl group may be substituted with a methyl group.

Next, the repeating unit (II) in the present invention
The substituent R ₁ constituting the methacrylimide structural unit of the methacrylimide group-containing polymer is a hydrogen atom or an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an aromatic hydrocarbon group or an alicyclic hydrocarbon group. It is chosen from the inside.

Considering the heat resistance of the methacrylimide group-containing polymer of the present invention, R ₁ in the general formula (I) is hydrogen atom, methyl group, ethyl group, propyl group,
Preferably selected from the group consisting of cyclohexyl, R ₁
Particularly preferred are those in which is a methyl group.

The content of the repeating units (I) and (II) is in the range of 40 to 80% by weight and 20 to 60% by weight, respectively, and further, the content of the repeating units (I) and (II) is contained. The total amount is preferably 90 to 100% by weight. Repeating units (I) and (II)
If the total content of each of the above is less than 90% by weight, it becomes difficult to obtain heat resistance and thermal stability that are practically satisfactory. The repeating unit (I) has a large contribution to the heat resistance of the methacrylimide group-containing polymer relative to the repeating unit (II), and thus has a function of improving the heat resistance of the polymer. When the content of the repeating unit (I) is less than 40% by weight, it is difficult to contribute to the improvement of heat resistance, which is not preferable. If the amount exceeds 80% by weight, the content of one of the repeating units (II) almost disappears, so that the heat resistance is excellent, but the mechanical strength is insufficient, which is not preferable.

Substituent R ₂ constituting the repeating unit (III)
Is a residue of an unreacted unit or an intermediate unit formed when obtaining the methacrylimide group-containing polymer according to the present invention, and the smaller the content of the repeating unit (III), the higher the thermal stability. Becomes R ₂ is specifically a carboxyl group, an aliphatic ester group having 1 to 6 carbon atoms, or an aliphatic amide group having 1 to 18 carbon atoms or an aromatic amide corresponding to the above formulas (I) and (II), respectively. Group, or an alicyclic amide group. Of these, a carboxyl group and an aliphatic ester group having 1 to 6 carbon atoms are particularly preferable. Further, the repeating unit (III) may have two or more different R ₂ groups at the same time.

The content of the repeating unit (III) in the methacrylimide group-containing polymer of the present invention is 0 to 10% by weight, preferably 5% by weight or less, more preferably 2% by weight or less. When it exceeds 10% by weight, the thermal stability of the methacrylimide group-containing polymer is lowered, and the molding temperature range of the molding material is practically narrowed.

The methacrylimide group-containing polymer according to the present invention preferably has a melt index (measured at 300 ° C./10 kg load) of 1.0 g / 10 minutes or more. If the melt index is less than 1.0 g / 10 minutes, sufficient fluidity may not be obtained when used as an injection molding material.

[0018]
A specific example of producing the methacrylimide group-containing polymer according to the present invention will be described below. For example, a methyl methacrylate polymer and aniline may be used in the presence of a solvent such as dimethylformamide at 100 ° C. or higher to 3
The reaction is carried out at a temperature of 50 ° C. or lower and in the presence of an inert gas such as nitrogen gas. The reaction product obtained after this has the following formula (I
V) R ₁ —NH ₂ (IV) (R ₁ is a hydrogen atom or _one of an aliphatic, aromatic or alicyclic hydrocarbon group having 1 to 18 carbon atoms.)
A compound represented by (hereinafter abbreviated as imidizing agent (IV)),
For example, methylamine is added and reacted again at a temperature of 100 ° C. or higher and 350 ° C. or lower and in the presence of an inert gas such as nitrogen gas, and then a volatile substance or an unreacted imidizing agent is obtained from the obtained reaction product. (IV) is separated and removed to obtain two different methacrylimides such as repeating units (I) and (II), for example, a methacrylimide group-containing polymer containing N-methylmethacrylimide and N-phenylmethacrylimide. .. The methacrylimide group-containing polymer produced as described above exhibits excellent heat stability, heat resistance, moldability and transparency. In addition to the above, imidization by simultaneously reacting different imidizing agents can be appropriately adopted.

As a raw material polymer for obtaining this methacrylimide group-containing polymer, a methyl methacrylate polymer,
A methacrylic acid polymer, a copolymer with another vinyl monomer copolymerizable therewith, or a blend thereof can be used. If the intrinsic viscosity of these raw material polymers is too low, the fluidity is excellent, but the mechanical strength is low, and it becomes difficult to obtain a good methacrylimide group-containing polymer molding material. Therefore, the intrinsic viscosity is 0.25. As described above, it is preferable to use one having a value of 0.3 or more. Vinyl monomers copolymerizable with methyl methacrylate or methacrylic acid include styrene derivatives such as styrene and chlorostyrene, olefins such as ethylene and propylene, vinyl cyanide derivatives such as acrylonitrile, vinyl halides such as vinyl chloride, and chlorides. Examples thereof include vinylidene halide such as vinylidene. These include, for example, chemical resistance, ozone resistance, and methacrylimide group-containing polymers.
Although it imparts additional functions such as flame retardancy, fluidity and film-forming property, the content of the polymer derived from these other copolymerizable vinyl monomers is not limited to the above formula (III The content of the repeating unit represented by (4) is particularly preferable, and the content is 0 to 5% by weight. If it exceeds 5% by weight, the thermal stability of the methacrylimide group-containing polymer tends to decrease.

The methacrylimide group-containing polymer according to the present invention can be used as it is as a raw material for various molding processes such as injection molding, press molding or extrusion molding. Further, other resins such as ABS resin and polyester resin such as polybutylene terephthalate, 6-
It can be blended with polyamide resins such as nylon and 4,6-nylon to improve impact resistance, chemical resistance, heat resistance and the like. In addition, glass fiber, carbon fiber,
Lubricants, mold release agents, heat stabilizers, types and amounts that do not impair the properties of fillers and resins such as talc and calcium carbonate,
Other additives such as flame retardants, colorants, and ultraviolet absorbers can be added.

The methacrylimide group-containing polymer according to the present invention is made into a desired molded article by various molding methods such as injection molding, extrusion molding, press molding, blow molding and calendar molding, and has excellent heat resistance and mechanical properties. It can be used in applications that make full use of the dynamic characteristics, but in particular, the excellent characteristics in melt flowability and thermal stability include processing condition width during molding processing, such as the size, shape or molding temperature of molded products, molding It can be advantageously performed from the viewpoint of cycles and the like.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, "parts" means parts by weight. The methods for measuring various physical properties in the examples are as follows. 1) Melt index It was measured according to ASTM D-1238. The measurement conditions were a parel temperature of 300 ° C. and an extrusion load of 10 kgf. 2) Thermal stability test The resin polymer sample was pressed at 330 ° C using a press molding machine.
And, it is inserted between two press plates heated to 350 ° C. and kept under pressure for 30 minutes. Then, this is cooled to Tg-30 degreeC with a press plate, and a molded product is taken out. The presence or absence of foaming of the obtained molded plate was visually observed. 3) IR spectrum An IR spectrum was measured in the range of 800 to 4000 cm ^{-1 by} the KBr method using an IR spectrometer. 4) Elemental analysis With a CHN coder, the nitrogen atom content (wt%) of each polymer
Was measured.

Example 1 A methyl methacrylate polymer (intrinsic viscosity of 0.3) was placed in a reactor having an inner volume of 1.5 liter equipped with a jacket heater.
2) Add 100 parts, 180 parts of dimethylformaldehyde, and 120 parts of aniline, and after sufficiently replacing with nitrogen, 150
The polymer was dissolved by stirring at a temperature of up to 0 ° C. Then 220
The reaction was carried out at a temperature of ° C for 3 hours. After completion of the reaction, the product was recovered and dried in vacuum at 150 ° C. to obtain a white powdery polymer. (End of first stage reaction). Subsequently, 100 parts of the polymer obtained in the first reaction, 13 parts of methylamine and 350 parts of toluene.
And 240 parts of methanol were placed in a reaction vessel, the atmosphere was sufficiently replaced with nitrogen, and the mixture was reacted at 230 ° C. for 2 hours (the second stage reaction was completed). After the reaction was completed, the product was recovered and purified to obtain a white powdery polymer. The polymer was heated at a barrel temperature of 280 to 3 by a devolatilization type molding device including a barrel, a piston and a die.
It was extruded under the condition of 50 ° C. to obtain a transparent strand polymer. As a result of IR spectrum measurement and elemental analysis of the purified dried product of the trace amount sample collected at the end of the first stage reaction, absorption based on the imide structure was confirmed from the IR absorption spectrum, and absorption based on the amide group was not confirmed. It was Further, it was found from the elemental analysis that the sample contained about 100% by weight of the structural unit of n-phenylmethacrylimide. In the same manner, regarding the shaped strand polymer of the white powdery polymer which was subjected to the second stage reaction, F
Absorption based on the imide structure was confirmed from the T-IR absorption spectrum. Furthermore, it was found from the elemental analysis that the structural unit of N-phenylmethacrylimide was about 80% by weight and the structural unit of n-methylmethacrylimide was about 20% by weight. The melt index of the obtained strand polymer was 2.5 g / 10 minutes. Further, when a thermal stability test was conducted using a press molding machine using the polymer, foaming was not confirmed even at molding temperatures of 330 ° C and 350 ° C. The above reaction conditions, composition analysis results and test results are summarized in Table 1.

Examples 2 to 3 Based on Example 1, as shown in Table 1, the same operation as in Example 1 was carried out except that the kind of amine used as an imidizing agent and the charged amount were changed to obtain a reaction product. It was Table 1 shows the reaction conditions, composition analysis results and test results.

Comparative Example 1 Internal volume of 1.5 equipped with reagent injection container and jacket heater
In a liter reactor, 100 parts of methyl methacrylate polymer (intrinsic viscosity of 0.32), 150 parts of toluene and 70 parts of methanol were charged, and after sufficiently substituting with nitrogen, the temperature was raised to 230 ° C. and stirred to dissolve the polymer. Let Then, at a temperature of 230 ° C., 30 parts of methylamine was made into a 50% methanol solution from a reagent injection container, and then added to the reaction container to obtain 2
The reaction was carried out at 30 ° C for 2 hours. After the reaction was completed, the product was recovered and purified to obtain a white powdery polymer. This polymer was extruded by a devolatilization type molding device including a barrel, a piston and a die at a barrel temperature of 280 to 320 ° C. to obtain a transparent strand polymer. The methacrylimide structure was confirmed by IR spectrum measurement. In addition, the polymer had about 1 structural unit of methylmethacrylimide as determined by elemental analysis.
It was found to contain 00% by weight. The melt index of the obtained polymer was 20 g / 10 minutes. Further, when a heat stability test was carried out with a press molding machine using the polymer, a transparent uniform plate was obtained at a molding temperature of 330 ° C., but remarkable foaming was observed inside at a molding temperature of 350 ° C. The above reaction conditions, composition analysis results and test results are summarized in Table 1.

Comparative Example 2 Internal volume of 1.5 equipped with reagent injection container and jacket heater
In a liter reactor, 100 parts of methyl methacrylate polymer (intrinsic viscosity 0.32) and dimethylformamide 18
1 part after adding 0 part and 120 parts of aniline and thoroughly substituting with nitrogen
The polymer was dissolved by heating to 50 ° C. and stirring. Then
The reaction was carried out at a temperature of 220 ° C. for 2 hours. After completion of the reaction, the product was recovered and purified to obtain a white powdery polymer. This polymer was extruded by a devolatilization type molding device composed of a barrel, a piston and a die at a barrel temperature of 280 to 350 ° C. to obtain a strand polymer. The methacrylimide structure was confirmed by IR spectrum measurement. Further, it was found from the elemental analysis that the polymer contained about 100% by weight of the structural unit of phenylmethacrylimide. The melt index of the obtained polymer was 1.0 g / 10 minutes or less.

Comparative Example 3 A reaction product was obtained in the same manner as in Comparative Example 1 except that the kind of the amine used as the imidizing agent and the charging amount were changed as shown in Table 1 according to Comparative Example 2. The reaction conditions, compositional analysis results and test results are summarized in Table 1.

Table 1 shows the reaction conditions, composition analysis results and test results of the above Examples and Comparative Examples. Table 1 also shows the test results of polycarbonate (commercial item) and polymethylmethacrylate (commercial item) measured under the same conditions as a reference example.

From Table 1, the following will become clear. 1) The methacrylimide group-containing polymers according to the present invention obtained in Examples 1 to 5 have an excellent balance of fluidity, thermal stability and heat resistance. 2) Such an excellent performance balance is exhibited by having two different methacrylimide structures in the methacrylimide group-containing polymer. For example, a polymer containing 100% by weight of an N-methylmethacrylimide structure as in Comparative Example 1 has not yet obtained sufficient heat resistance. 3) Further, in the polymer having a reduced N-methylmethacrylimide group content as in Comparative Example 2, the fluidity is improved, but the thermal stability or heat resistance is significantly reduced. 4) The polymer containing 100% by weight of the Nn-butylmethylmethacrylimide structure showing high fluidity as in Comparative Example 3 has good fluidity and thermal stability,
The heat resistance is extremely low. 5) The methacrylimide group-containing polymer according to the present invention exhibits excellent balance of heat resistance, thermal stability and fluidity as compared with other transparent resin materials such as polycarbonate and polymethylmethacrylate.

[0030]

[Table 1]

[0031]

The methacrylimide group-containing polymer according to the present invention is excellent in heat resistance, thermal stability at the time of molding and melt flowability, and has an excellent performance balance between them. The utility value above is extremely high.

Front Page Continuation (72) Inventor Kaoru Nagamori 3 Kaigan Dori, Toyama City, Toyama Prefecture Mitsubishi Rayon Co., Ltd. Toyama Office

Claims (5)

[Claims] 1. The following general formulas (I), (II) and (II)
A methacrylimide group-containing polymer containing each repeating unit represented by I) in the polymer, wherein the content of the repeating units represented by the general formulas (I) to (III) in the polymer is A methacrylimide group-containing polymer which is 40 to 80% by weight, 20 to 60% by weight, and 0 to 10% by weight, respectively, based on the weight of the polymer. [Chemical 1] (In the above formulas (I), (II) and (III), R ₁ represents a hydrogen atom or an aliphatic, aromatic or alicyclic monovalent hydrogen group having 1 to 18 carbon atoms, and R ₂ represents a carboxyl group or a carbon atom. Number 1
It represents an aliphatic ester group of 6 or an aliphatic amide group having 1 to 18 carbon atoms, an aromatic amide group or an alicyclic amide group. ) 2. The methacrylimide group-containing polymer according to claim ₁ , wherein R ₁ in the general formula (II) is a methyl group. 3. The total content of the repeating units represented by the general formula (I) and the repeating units represented by the general formula (II) is 90 to 100% by weight.
The methacrylimide group-containing polymer according to any one of items 2 and 3. 4. The method according to claim 1, wherein R ₂ in the general formula (III) is a carboxyl group or an aliphatic ester group having 1 to 6 carbon atoms. The methacrylimide group-containing polymer described. 5. The provisions of ASTM D1238 (however, 30
The methacrylimide group-containing polymer according to any one of claims 1, 2, 3, and 4, which has a melt index of 1.0 g / 10 minutes or more at 0 ° C, 10 kg load). ..